Final answer:
The correct statement is that pancreatic juice contains enzymes and ions that aid digestion in the small intestine. Pancreatic juice's bicarbonate neutralizes stomach chyme's acidity, and its enzymes aid in breaking down proteins, carbohydrates, and fats.
Step-by-step explanation:
True Statement about Digestive System Secretions
The statement that is true regarding one of the secretions that contribute to digestion is 'Pancreatic juice contains enzymes and ions that aid digestion in the small intestine.' Pancreatic juice, produced by the pancreas, contains a variety of enzymes that are required for the digestion of proteins and carbohydrates. It also contains high levels of bicarbonate which neutralizes the highly acidic nature of the chyme coming from the stomach. Enzymes such as pancreatic lipase participate in lipid digestion, and pancreatic nuclease is essential for nucleic acid digestion. This supports the optimal functioning of digestive processes in the small intestine.
It is important to note that while intestinal juice also contributes to digestion in the small intestine, it does not emulsify fats -- that function is primarily attributed to bile, which is produced by the liver and stored in the gallbladder. Saliva, on the other hand, does not contain hydrochloric acid; it has enzymes like amylase for the initial breakdown of carbohydrates. Finally, gastric juice, found in the stomach, does contain enzymes that begin the digestion of proteins; however, it breaks down food into chyme, not the other way around.